The association of myopathy with MED has been noted before and is associated with mutations in both COL9A3 [Bonnemann et al., 2000; Lohiniva et al., 2000] and COMP, in particular mutations in those exons of COMP that encode the C-terminal domain of COMP [Jakkula et al., 2003; Kennedy et al., 2005b]. Here, COMP is linked to multiple epiphyseal dysplasia.